Mercedes R-class (W251)

Debut: 2005
Maker: Mercedes-Benz
Predecessor: no
Crossover, everybody talks crossover these days. Mercedes-Benz is no exception. After A-class and CLS-class, it is pushing the concept of crossover vehicles to new height with the R-class.

The R-class is something between estate car, MPV and SUV. Its exterior design looks as if a crossover between estate and MPV, being bigger than the former and sleeker than the latter. It offers 6 seats in 3 rows, plus very generous passenger and cargo room, so that it can compete with conventional MPVs. However, the relatively less playing kits and high loading floor works more like estate cars. Moreover, the R-class has a compulsory 4-wheel-drive system and high ground clearance to enable some offroad ability. Therefore it is also an alternative to SUVs.

You might find all these sounds familiar. Yes, Chrysler Pacifica already has all such attributes. In fact, the two cars were developed by the same team of Mercedes-Benz engineers (of course, Chrysler's engineers also involved the American car). But it is not to say they were sister cars. In fact, their similarity is mainly in concept rather than sharing components. The only common component is the E-class-derived 5-link rear suspensions, but the version adopted by R-class has more aluminum components for lower unsprung weight, hence smoother ride. It also gets the Airmatic DC adaptive damping and air springing which the cheaper Chrysler doesn't. Apart from that, both cars share little components - they have their own engines, different transmissions (the R-class employs the latest 7G-Tronic while the Chrysler still rely on the previous 5-speed automatic), different front suspensions (R-class has double wishbones while Pacifica uses cheaper MacPherson struts) and of course, the Mercedes is equipped with many luxurious features and safety equipment that the Chrysler cannot dream of.

The 4WD systems are also different. The R-class system uses a regular center differential to split 50% torque to both axles in normal conditions. Because the differential does not have any limited slip function, it uses the hardware of ABS to lock the slipping wheels in critical conditions (i.e. when one axle slip, the computer will apply braking to the wheels of that axle so that more torque will be transferred to the other axle). This sounds quite cheap, but the Pacifica's system is even cheaper - it uses viscous-coupling to transfer torque to the rear wheels in case of slippery. This means it is only a part-time 4WD.

In fact, the R-class is a closer sister to the new ML-class SUV instead. They are both produced in Mercedes' plant in Alabama, USA. Naturally, they share engines, transmissions, suspensions and the 4WD system. (haha, sorry for wasting your time in the above paragraphs - ed)

At 5.16 meters long, 1.92 meters wide and 1.66 meters tall, the R-class is by all means a jumbo vehicle. Its 3215 mm wheelbase is even longer than a long-wheelbase S-class ! in addition to the high roof, no wonder the cabin feels significantly more spacious than the S-class !

The negative side is weight. The R-class tips the scale at almost 2.2 tons. This means R350's 272-horsepower 3.5-litre V6 is no where as firebreathing as in the C and E-class. Luckily, it is mated with a 7-speed automatic gearbox, otherwise performance would have been sluggish. R500's long-serving 306-horsepower 5.0 V8 is a little quicker, but our hope is placed on the forthcoming 32-valve 5.5-litre V8, which will add another 60 horsepower. Of course, AMG's new 6.3 V8 will top the range next year with 510 horsepower. By then maybe it would become the world's first estate / MPV / SUV / Sportscar crossover ?

Back to the cabin. Naturally, the first 2 rows are very roomy, especially because the second row is also a pair of independent chairs. However, the most shocking is that the third row can accommodate adults of 6' 2" tall, sitting behind occupants of the same height. The only thing the third row passengers need to tolerate is shoulder room, as the seat is recessed between the rear wheels. Like SUVs, the seats are mounted higher than regular cars to give the occupants a commanding view. This, accompany with large windows and panoramic glass roof, makes the cabin bright and airy.

Compare to other recent Mercedes, the dashboard styling is conservative while the build quality is slightly off the standard of German-built Mercedes. Nevertheless, the leather seats are comfortable, the chassis feels solid and the noise insulation is remarkable, therefore this cabin is still a first class environment. One thing really distinguish the R-class from Chrysler Pacifica and others is market positioning. This can be revealed in its price (start from an eye-popping US$50,000 for R350 and US$65,000 for a fully-loaded R500) as well as the luxurious environment. For example, you can have a pair of LCD entertainment system installed behind the front backrest for the second row passengers. Therefore R-class is also an alternative to luxurious cars.

How does it drive? currently, only American version has been tested. Predictably, its high-profile tires and soft-set suspensions bias towards the comfort side. In addition to the ultra-long wheelbase, the R-class rides superbly smooth. Does this mean the handling suffer ? Not really. Mercedes is always a Mercedes. No matter how comfortable it biased, it always ensure a good level of handling. (The same cannot said to Japanese cars) This is why it has Airmatic DC. If you switch the air suspensions to Sport mode, it will stiffen the springing and damping to keep body roll in check, resulting in a rather nimble handling character. Of course, this is still a very big, tall and heavy car thus you cannot compare it with the S-class, but by MPV and SUV standard it is easily one of the best.

Strangely, the R-class is the world's first luxurious MPVs, although Mercedes and BMW have been planning such cars for a decade and a half. Why does it take so long to realize ? I guess the relatively less demand for such cars does not justify the cost of building a standalone platform. That's why Mercedes had to wait until the redesign of ML-class to share platform. Will BMW follow its footprints with a X5-derived people carrier ? We shall see.

European R-class

The R-class' main market is in the United States. For European market, a shorter R-class will be offered to suit the narrower and twistier roads. Its length will slip into the 5-meters barrier (at 4922 mm), with a shorter wheelbase as well. As a result, the full-size rearmost seats will become child seats only. To deliver sportier handling that European customers prefer, the suspensions will have thicker anti-roll bars and the steering rack will be retuned to deliver more feedback. Besides, the European car will have a choice of 224 hp 3.2-litre common-rail V6 turbo diesel, in the badge of R320CDI.
The above report was last updated on 7 Aug 2005. All Rights Reserved.


General remarks


Front-engined, RWD
Front-engined, RWD

Steel monocoque
Steel monocoque
Mainly steel
Mainly steel
Length / width / height 5157 / 1922 / 1656 mm 5157 / 1922 / 1656 mm
Wheelbase 3215 mm 3215 mm
V6, 90-degree
V8, 90-degree
3498 cc
4966 cc
Valve gears
DOHC 24 valves, VVT
SOHC 24 valves, VVT
Other engine features

Max power
272 hp 306 hp
Max torque
258 lbft 339 lbft
7-speed automatic
7-speed automatic

Suspension layout
F: double-wishbone
R: multi-link
F: double-wishbone
R: multi-link

Suspension features
Adaptive air springs + damping
Adaptive air springs + damping
Tyres front/rear

Kerb weight
2130 kg
2165 kg

Top speed
143 mph (c)
149 mph (c)

0-60 mph (sec)
7.8 (c)

0-100 mph (sec)

Performance tested by: *C&D

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